A company uses a continuous-review inventory system for a product. The weekly demand of the product approximately normally distributed with a mean of 706 units and a standard deviation of 30 units. Furthermore, weekly demands are independent. That is, the demand on a particular week does not related to the demand on any other week. The company buys the product from a supplier with an order lead time of 4 weeks.
What is the appropriate safety stock if the company wants to have a 96% service level?
Note: This question is in regards to Distribution of demand during lead time